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#167509 - 08/14/07 05:44 PM What is your policy concerning older wiring  
ChicoC10  Offline
Member
Joined: May 2007
Posts: 169
CA
Hi everyone-
I do mostly residential work including a fair amount of service/remodel.
In my town there are many older houses from knob and tube on through the various changes in cable construction right up to , of course, modern romex.
I personally have a policy that I won't add any load to any existing older wiring unless I can verify without a doubt that it is lightly loaded to begin with. I especially won't touch knob and tube or the tar covered stuff with the wound insulation that unravels as soon as you touch it. You know, the stuff that has about 2 inches of wire in the box and was soldered and taped.
Failing that I will insist on pulling new circuitry to the new loads and even unload the older wiring some if possible.
This, of course, requires that a relatively modern service has been added at some point along the years and that some load and distribution is still available.

But from time to time I'm also asked if I think the older wire with no equipment ground is safe and I'm not quite sure how to answer this question. I mean 40 years from now how safe will people think the house your living in right now is based on whatever code changes have been put in place by then?
My general opinion is that as long as it hasn't been hacked and re-hacked over the years or been damaged by all the ways possible (too many to list) that it should be as safe as it was when the house was built to the codes if effect during that era. If some obvious chimpanzee work has been done I suggest they have me clean that up. Even though I would prefer to live in a house with grounded wiring I find it hard to suggest that someone go to the high cost and extreme inconvenience to completely rewire their home, especially if they weren't already in the course of an extensive remodel when it would be the most cost effective time for such an action.
Should I be dissembling every box (with it's 2 inch soldered connections and wound insulation) to ring out or megger the entire system, buy an endoscope and inspect inside the walls, or leave this kind of consultation to someone who's equipped to do just that?

Any opinions or insights into this dilemma would be appreciated.
Thanks
Vince


Work Gear for Electricians and the Trades

#167512 - 08/14/07 06:28 PM What is your policy concerning older wiring  
ChicoC10  Offline
Member
Joined: May 2007
Posts: 169
CA
.

Last edited by pauluk; 08/15/07 11:01 AM. Reason: Double post

#167517 - 08/14/07 09:31 PM Re: Oops- here's the post "Older wiring" [Re: ChicoC10]  
Gregtaylor  Offline
Member
Joined: Mar 2005
Posts: 212
Boise, Idaho, USA
I think the way you go about it is about right and much more conscientious (sp?) than most. Everything you build today is made of used parts tomorrow.


#167525 - 08/15/07 01:52 AM Re: Oops- here's the post "Older wiring" [Re: Gregtaylor]  
Sixer  Offline
Member
Joined: Aug 2005
Posts: 265
Canada
Since the insurance companies won't cover for K&T, we replace it.

The only thing we've found to be bad with K&T (other than the fact is has no ground) is in ceiling light boxes. Over the years heat from the bulbs makes the insulation brittle and crumble off when you touch it.

There is one other issue that's been brought up: was K&T wiring ever designed to have insulation around it? Most homes of the K&T era weren't insulated, but added it afterwards.

When clients ask if it's unsafe, I explain that although it still works, it's 50+ years old and due to be replaced with modern grounded wiring before problems can arise.


Sixer

"Will it be cheaper if I drill the holes for you?"

#167528 - 08/15/07 03:17 AM Re: Oops- here's the post "Older wiring" [Re: Sixer]  
e57  Offline
Member
Joined: May 2003
Posts: 2,876
S.F.,CA USA
I let people keep what they can, and if they want to, for the sake of finishes, and necessity. But within reason due to loading, code, and applicable purpose. A case by case basis.

The purpose of the EGC is to bring the exterior metal of appliances and fixtures, or other potential contacts to the same electrical potential of other items that would also be grounded. Water, gas and drain plumbing. Foundations, footings and slabs. HVAC duct work, and structual steel. CATV, Phone and network wiring.

Not all K&T is un-grounded, often you open the wall and find that it is, and still intact, or had been grounded to plumbing as was allowed right up to 1993.

3-wire K&T originally wired that way, or converted in prior work is a hazard IMO. For a few reasons other than just what some might see as a fear of MWBC's. 1.) wiring not intended originally to be 3-wire should all remain phased the same IMO due to possible additions that have been done prior. And 2.) during the period of time that 3-wire K&T was allowed to be originally installed was a horrible time for workmanship so I have found, coincidently it coinsides with thermoplastic wiring. I all too often find unsoldered splices on wiring of this period. Not to mention the 3-wire circuit was a new thing to the persons installing it, as prior to that, no 3-wire general purpose circuits were allowed past the panel unless it was for equipment, or so it seemed.

Well more than 50% of plug and cord items in the home do not require a ground outside of kitchens, baths, and garages. If polarized outlets are all they need, why change them? Surface lighting too if the load is not changing. If given the choice to ground the existing wiring, or to re-run new, I would opt for new. But not out of my own necessity. However if asked to convert say a K&T light to 20 cans - no due to increased load. Keep a kitchen or bath in K&T - no due to grounding and load... Put a light in the shower - No due to grounding. Add a bunch of outlets for a home office - no due to load and grounding. Add a bunch of outlets for the sake of convieniance - yes I'll keep the existing wiring. Add a bunch for the sake of having multiple places to plug in space heaters due to the lack of proper heating the building then definately no...

If there were evidence of deteriorated insulation, it too would be an option for repair or replacement - depending on the cause. "Hack wiring" of any age would be the same - repair or replace.

If the customer is not adding insulation, or load, or requires a ground for a specific reason - why replace one 15a circuit of X amount of load for a new circuit with X amount of load with an unused EGC? If they have the walls open that is one thing, but if not that is an unnecessary multi-trade change order IMO. If you were to say go price a service up-grade here, and also demand that the customer re-wire the whole building due to the presence of K&T, you: 1.) May not get the job. 2.) Could be explaining to the license board as to why you're pushing for unnecessary work. Who may or may not see it as justified as you thought it was. If the customer wants it changed, that is another story - but you can't force it upon them unless there is a reason.

Short soldered splices in black iron pipe... Just re-pull it. Easy money...


Mark Heller
"Well - I oughta....." -Jackie Gleason

#167560 - 08/15/07 12:53 PM Re: Oops- here's the post "Older wiring" [Re: e57]  
Sixer  Offline
Member
Joined: Aug 2005
Posts: 265
Canada
Originally Posted by e57

Not all K&T is un-grounded, often you open the wall and find that it is, and still intact, or had been grounded to plumbing as was allowed right up to 1993.

It's very rare to see grounded K&T in these parts, and the grounding we've seen is questionable at best.
Originally Posted by e57

If the customer is not adding insulation, or load, or requires a ground for a specific reason - why replace one 15a circuit of X amount of load for a new circuit with X amount of load with an unused EGC? If they have the walls open that is one thing, but if not that is an unnecessary multi-trade change order IMO. If you were to say go price a service up-grade here, and also demand that the customer re-wire the whole building due to the presence of K&T, you: 1.) May not get the job. 2.) Could be explaining to the license board as to why you're pushing for unnecessary work. Who may or may not see it as justified as you thought it was. If the customer wants it changed, that is another story - but you can't force it upon them unless there is a reason.

In this area, there are no insurance brokers who will insure for K&T, period. You sell your home, the insurance broker gives the new owner has 60 days to replace the K&T. The brokers are even phoning people they insure who live in older homes if they have K&T. Once they know about it, it has to be changed. Now they're starting to request for verification letters from a certified EC that there is no K&T wiring in the home.

It's not a case of the ECs forcing the issue here just to drum up more work, it's the insurance underwriters. We hate doing re-wires, but it's become a necessary evil we have to deal with. There's obviously a reason why the underwriters consider K&T to be such a high risk.


Sixer

"Will it be cheaper if I drill the holes for you?"

#167812 - 08/20/07 10:52 PM Re: Oops- here's the post "Older wiring" [Re: Sixer]  
wire_twister  Offline
Member
Joined: Jul 2007
Posts: 265
Georgia USA
Shure there is, MONEY, when somebody refuses to rewire and takes the Ins. company to court for dropping them the Ins. co. will just raise the premiums to a ridiculous ammont, and inform all other ins. co. in the area about the K&T so they can all raise their rates accordingly.


Jimmy

Life is tough, Life is tougher when you are stupid

#167823 - 08/21/07 07:04 AM Re: Oops- here's the post "Older wiring" [Re: Sixer]  
iwire  Offline
Moderator
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
Originally Posted by Sixer
There's obviously a reason why the underwriters consider K&T to be such a high risk.


Yes there is a reason....they have no idea what they are talking about. I highly doubt that they have any real proof of a problem. Un-touched K & T is very safe, the problems happen when the unqualified mess with it.

In some areas insurance companies are refusing homes that still use fuses. crazy


Bob Badger
Construction & Maintenance Electrician
Massachusetts

#167825 - 08/21/07 07:43 AM Re: What is your policy concerning older wiring [Re: e57]  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Originally Posted by e57
Not to mention the 3-wire circuit was a new thing to the persons installing it, as prior to that, no 3-wire general purpose circuits were allowed past the panel unless it was for equipment, or so it seemed.


When were multiwire branch circuits first allowed then?



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